Rotary spray gun

ABSTRACT

A rotary spray gun having a trigger operated motor and gating mechanism, the motor being energized prior to opening of the gating mechanism, the gating mechanism thereafter being automatically opened to a preselected amount, thereby to discharge a predetermined width of spray pattern with minimal formation of droplets.

United States Patent Patented Aug.,l7, 1971 I Assignee Electro Engineering Products Co., Inc.

ROTARY SPRAY GUN Relerences Cited Primary Examiner-M. Henson Wood, Jr.

Assistant Examiner-Edwin D. Grant Attorney-Dressler, Goldsmith, Clement & Gordon 10 Claims, 7 Drawing Figs. U.S.Cl.... 239l2 l8.5, ABSTRACTz A rotary spray gun having a trigger operated 239/332, 239/451 motor and gating mechanism, the motor being energized prior Int. Cl. B05b 3/02 to opening of the gating mechanism, the gating mechanism Field of Search 239/214, thereafter being automatically opened to a preselected 215, 218.5, 237, 302, 451, 455, 526, 216, 329, amount, thereby to discharge a predetermined width of spray v 331 332 pattern with minimal formation of droplets.

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I 0; 55 f I 108 I ill? ROTARY SPRAY GUN This invention relates to a spray gun adapted to spray liquids, such as paint and the like. The invention is particularly concerned with a trigger operated control mechanism for starting and stopping a rotary attenuator and the flow of liquid thereto, and for opening and closing a gating mechanism for the attenuator to allow the discharge of liquid therefrom and from the spray gun in preselected widths of spray patterns.

Spray mechanisms embodying the present invention are of general utility for spraying any suitable liquid and may have any desired form and shape. They are preferably portable and hand operable and are desirable of light weight.

The spray gun includes a self-contained electric motor for rotating an attenuator, a tank or receptacle for liquid to be sprayed and a conveyor for moving paint from the receptacle.

to the attenuator. The conveyor may comprise an open ended feed tube extending into the receptacle and a screw impeller surrounded by the tube and cooperable therewith. The attenuator may be a smooth surface inverted cone rotatably mounted in the housing of the spray gun for receiving the liquid conveyed through the feed tube by the screw impeller. The paint is discharged peripherally of the attenuator in a bank of an adjustable width, the band width being adjusted by a gating mechanism. Such a spray gun is generally described in Kanarek US. Pat. No. 3,074,650, the disclosure of which is inccrporated herein by reference.

In spray guns of the character illustrated in that patent, manually adjustable means for adjusting the spray band width discharged through the gating mechanism are provided. Separate means, associated with the spraying mechanism are provided for energizing the motor which rotates the screw impeller and attenuator. Trigger means for energizing the motor are shown and described in other patents, such as, for example',U.S. Pat. No. 3,197,142 to Gold etal.

A number of disadvantages inhere in the utilization of separate means to energize the motor and to manually adjust the opening through the gating mechanism and are characteristic ofprior art spray guns, such as those just referred to.

For example, if the gating mechanism is opened before the motor is energized, droplets of paint spew forth from the spray gun before the attenuator reaches operating speed. Also, if the gating mechanism is to be opened after the motor is energized and the attenuator begins to rotate, awkward manipulation of the manual gating mechanism to open it, such as by a handle on the spray mechanism housing, is required.

In accordance with the present invention, means'associated with the trigger are provided to initiate paint feeding and operation of the attenuator prior to the opening of the gating mechanism. Thereafter, the gating mechanism is automatically opened to a preselected (and adjustable) amount, thereby to discharge liquid in a predetermined band width of the spray. That means that after an adjustment is made for setting a desired width of spray pattern, all that one need to do is to grip the trigger to start the motor, after which the gating mechanism automatically opens to the predetermined setting.

These and other advantages and features of the present invention will become apparent from the following description and drawings, of which:

FIG. 1 is a side elevation of a sprayer of this invention;

FIG. 2 is a side elevation of the other side of the sprayer of FIG. ll;

FIG. 3 is a view partially in section of the interior of the paint sprayer of FIGS. 1 and 2;

FIG. 4 is a fragmentary bottom view taken substantially above line 4-4 of FIG. 3 with the gating mechanism in a closed position;

FIG. 5 is a view similar to FIG. 4 showing the gating mechanism in an open position; FIG. 6 is a bottom view of one of the gates of the gating mechanism of FIG. 3; and

FIG. 7 (with FIGS. 1 and 2) is a bottom view of the other of the gates of the gating mechanism of FIG. 3.

Referring now to the drawings, the reference numeral 10 designates a sprayer or spray gun embodying the principles of this invention. It is adapted to spray paint or any other suitable liquid. Spray gun It) includes a motor housing 12 in which is mounted a motor 14 having a drive shaft 16 depending therefrom. A hollow handle 18 fixed to housing 12 in any suitable manner forms a conduit for an electrical wire 20 which connects the motor 14 to an electric current source.

A barrel portion 22 having a generally cylindrical wall 24 is secured to the underside of housing 12 by a plurality of screws (not shown) accommodated in screw channels 26. Barrel 22 may be constructed generally in accordance with the barrel i1- lustrated in the aforementioned U.S. Pat. No. 3,074,650 and forms no part of this invention in and of itself. A paint can having threads engaging external threads 28 on barrel 22 is also provided.

The lower end of drive shaft 16 defines an axial bore 32 threaded to receive the threaded upper end portion of a screw impeller34. Screw impeller 34 may be made of any suitable material, but is preferably made of nylon which is inert and noncontaminating to the liquids to be conveyed thereby. The screw impeller 34 extends to a point spaced a short distance from the bottom of the can 30. The screw portion of screw impeller 34 is surrounded by an open ended tube 36. The upper end of tube 36 is suitably press fit into a central portion of barrel 22 to maintain it in a fixed position within the spray gun. Preferably the tube 36 is also formed of a material such as nylon which is inert and noncontaminating to the liquids to be conveyed by the screw impeller 34. Screw impeller 34 and tube 36 cooperate to elevate paint to an attenuator in a known manner.

The. upper end 38 of the screw impeller 34 which is threaded to mate with the threads of axial bore 32 may be separately formed of metal. Upper end 38 includes a flange or shoulder 40 which supports the generally conical attenuator or rotor 42 via a cooperating hub 43 thereon, which hub surrounds the lower end of drive shaft 16. A plate 44 overlies the upper serrated edge 45 of the attenuator 42 to define therewith a circumferential spray discharge opening 46 comprising a plurality of peripheral passages through which the paint to be sprayed is discharged peripherally of the attenuator. The attenuator 42 and plate 44 are keyed to the drive shaft to be corotatable therewith as by a flat on the shaft and complementarily configured mounting apertures on the plate and hub of the attenuator. The attenuator and plate assembly and its operation and function are described and illustrated in US. Pat. No. 3,074,650 in greater detail.

As best seen in FIG. 1, a spray opening 50 is defined by a recess in the upper edge of barrel portion 22 and terminates upwardly adjacent a lower complementary tapered edge portion 51 of the motor housing 12. It is through this spray opening that the paint or other liquid is discharged from the sprayer 10 for application to a surface to be painted. This opening is also illustrated in U.S. Pat. No. 3,074,560.

Opening 50 is normally closed by a gating mechanism which will now be described. The gating mechanism includes a first gate 60 and second gate 70 which are relatively movable between a position in which they completely shield spray opening 50 (FIG. 5) and variable intermediate positions in which they open to predeterminable degrees to permit spray discharge through spray opening 50 (FIG. 4).

The first or upper gate 60 comprises a generally circular upper portion 62 defining a central circular aperture 64 and terminates peripherally in a downwardly extending guard portion 66. Guard portion 66 comprises a segment of about and as seen in FIG. 3, includes a downwardly and outwardly sloping portion which terminates in a vertical flange portion. Guard portion 66 terminates at one end in a segment 67 which is generally U-shaped in transverse cross section. Circular portion 62 defines an eccentric pin channel 68 terminating at one end in an angular slot segment 69.

The second or lower gate 70 comprises a circular segment 72, a central circular aperture 74, a plurality of droplet breakup vanes 76 and a peripheral, downwardly extending guard segment 78 which comprises a downwardly and outwardly sloping portion and a vertical portion. Guard segment 78 extends for about 240 of the periphery of the circular segment 72.

Circular segment 72 also defines a pin channel 80 which is oppositely directed to the pin channel 68. Pin channel 80 terminates at its innermost end in an angular slot portion 82.

Gates 60 and 70 are retained in the position shown in FIG. 3 by a centrally apertured bolt 90 which is threadedly secured to the motor housing. Bolt 90 includes a threaded shank 92 and a circular shoulder 94 which is complementary to and is received in gate apertures 64 and 74. The bolt 90 terminates at its lower end in a shoulder 96 which contacts the lower surface of lower gate 70 to retain gates 60 and 70 in position. Bolt 90 receives a bushing 98 which is mounted on drive shaft 16 and which is rotatable with respect thereto. Thus, bolt 90 does not rotate with drive shaft 16.

In the nonoperating position of the sprayer 10, the gates 60 and 70 are positioned as best illustrated in FIG. 4. As there seen, the cam slots 68 and 80 intersect at the ends providing the angular slot portions 69 and 82, respectively, and diverge outwardly from each other. The angular slot portions 69 and 82 receive a tapered gate pin 100 which is reciprocably movable between the positions shown in FIGS. 4 and 5. Gate pin 100 is secured to gate link 102 which is movable longitudinally of itslength as illustrated in FlGS. 4 and 5, andin a link guideway 104 in the housing. The end of link 102 remote from the tapered gate pin 100 defines a notch 104 which is configured to receive a portion of trigger 106 so that as the trigger is oscillatably moved about its pivot 107 from the dotted line position shown in FIG. 3 rearwardly to the full line position shown in FIG. 3, the gate link 102 will be retracted rearwardly, thereby drawing gate pin 100 rearwardly from the position illustrated in FIG. 4 to that shown in FIG. 5. lntermediate the ends of gate link 102, a spring stud 108 is provided. Spring stud 108 receives one end of a spring 110, the other end of which is secured to a suitable retainer pin, such as bolt 112. Spring 110 is a tension spring tending to return the trigger to the position illustrated in dotted line in FIG. 3. Retraction of the trigger to the position shown in full line in FIG. 3 tensions the spring.

As the trigger is moved from the dotted line position of HG. 3 to the position of the trigger shown in solid line, gate pin 100 moves with the connected gate link 102. The gate pin slides within the pin channels 68, 80, thereby gradually oscillating the gates and camming them from the fully closed position of FIG. 4 to the fully open position of FIG. 5. As the gates are so cammed, an opening 113 of gradually increasing peripheral dimension is provided between U-shaped segment 67 and edge 114 of gate 70. This opening 113 confronts spray opening 50 so that the paint to be discharged passes therethrough.

The width of the opening 113 between segment 67 and edge 114 determines the width of the spray pattern discharging through spray opening 50. The width of this opening is preselected and predetermined by an adjustable cam assembly including cam 120 which is controlled by a control knob 122. Control knob 122 is secured to cam 120 so that as control knob 122 is rotated, cam 120, which as seen in HO. 3 is co centric in shape, is moved so that its peripheral surface is adjustingly spaced from a confronting rear surface of trigger 106. As trigger 106 is drawn rearwardly, it eventually contacts the confronting peripheral surface of cam 120 and is stopped thereby. The inside of the handle is provided with an abutment 124 fixed thereto. The cam carries a radially projecting limit segment 126 which at the desired limits of rotation of cam 120 contacts abutment 124. It is in this manner that the degree of opening of the gates 60 and 70 is adjusted to a preselected amount.

The motor 14 is energized through a microswitch 130 which is normallyclosed. When the motor is to be energized, thereby to convey paint by a screw impeller 34 to attenuator 42, the trigger as shown in phantom in FIG. 3 at 106 is gripped and moved rearwardlyfUpon the initial rearward movement, a

switch release abutment 132 on the trigger is withdrawn rearwardly from microswitch button 134. Therefore it is seen that very slight rearward movement of the trigger automatically energizes the motor through switch 130. That slight initial movement, however, does not move the gates with respect to each other and permits only movement of the tapered gate pin within the "lost motion slot segments 69, 82.

it is therefore seen that upon initial movement of the trigger, motor 14 is energized, paint is fed to the attenuator from tank 30 and the attenuator begins to rotate, all without discharge through spray opening 50 or through the gates. Thereafter, on continued rearward movement of the trigger, gate pin 100 leaves the slot segments 69, 82 and begins to traverse cam slots 68, 80. As this occurs, the gates rotate about the axes of their central openings 64, 74 to provide an opening 113 between edge 114 and U-shaped segment 67 in a very narrow spray pattern, which pattern widens until the triggers rearward movement is stopped by cam 120. Because the attenuator has started to rotate and been brought up to speed prior to opening of the gates, the discharge of droplets normally encountered when the gates are open upon starting of the motor, is precluded. Further, as soon as the motor has started and paint is fed to the rotor, the gates are automatically opened, contrary, for example, to the mode of operation of the paint sprayer described and illustrated in US. Pat. No. 3,074,650.

Means for varying the speed of the rotor is also provided as illustrated by control knob which is connected to a suitable speed control device 142 such as a potentiometer which is electrically connected to motor 14 via a solid-state control circuit 143 electrically connected to the potentiometer. The variable speed of the motor, not only provides for a variable discharge rate for the paint or the like to be sprayed, but also compensates for variable viscosities of the liquid to be sprayed.

In accordance with this invention, as has been illustrated and described, prior to the operation of the spray gun, the rate of spray discharge and width of the spray pattern may each be preselected and adjusted. Thereafter, it is only necessary to draw back on the trigger to operate both the motor and the gates. This very much simplifies the use and operation of the sprayer as compared to known sprayers.

Although we have described a preferred embodiment of this invention in considerable detail, it will be understood that the description is intended to be illustrative only, and that modifications may be made by those skilled in the art without departing from the spirit and scope of this invention.

What 1 claim is:

1. In a portable spray gun having a handle, a self-contained motor, a motor housing, a liquid supply container secured thereto, rotary means for discharging liquid from the spray gun peripherally of the rotary means and a movable gating mechanism for adjusting the width of the spray pattern discharged from the rotary means, a movable trigger means,

means operatively connected to said trigger means upon movement thereof for actuating said motor and means operatively connected to said trigger for moving said gating mechanism after said motor has been actuated between a closed position and a preselectable range of open positions to preselect the width of the spray pattern discharged from said spray gun.

2. In the spray gun of claim 1 wherein said gating mechanism comprises a pair of gate members having peripheral shielding flanges in the path of liquid discharged from said rotary means when the gating mechanism is in a closed position.

3. 1n the spray gun of claim 2 in which each of said gate members defines a slot eccentric to a central axis of said gate members, and said gate moving means includes a pin member in said slots.

4. 1n the spray gun of claim 3 in which said said pin member is secured to a reciprocable gate link operatively connected to said trigger means, said gate link being reciprocably movable with said trigger means.

' 5. In the spray gun of claim 1. further including externally adjustable means for limiting the range of movement of said trigger means thereby to preselect the width of the spray pattern discharged by said rotary means through said gating mechanism.

6. In a manual spray gun having a handle, a motor housing connected to the handle, a motor in the housing, rotor means for discharging liquid peripherally therefrom, means for supplying said rotor means with liquid to be sprayed, and a gating mechanism through which liquid discharged by said rotor means is adapted to pass, a trigger, said gating mechanism comprising a pair of oscillatable gates oscillatable between a closed position to intercept all of the liquid discharged by said rotor means and a range of preselectable openlpositions to allow discharge of liquid from said spray gun, and means for oscillating said gates connected to said trigger and to said gates.

7. In the spray gun of claim 6 wherein said oscillating means comprises a gate link and channels in said gates, said channels being eccentric to the axis about which said gates oscillate.

8. In the spray gun of claim 7 wherein said gate link is reciprocably movable with said trigger and mounts a gate pin positioned in said channels.

9. In the spray gun of claim 6 further including means for energizing said motor prior to oscillation of said gates connected to said trigger.

10. in the spray gun of claim 6 wherein said spray gun mounts a rotatable cam, said cam being positioned to contact said trigger and to limit the movement of said trigger to any one of said range of preselectable open positions thereby to preselect the width of the spray pattern discharged through said gating mechanism.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3,599,868 Dated August 17, 1971 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1, line 21, "surface" should be surfaced Col. 1, line 26, "bank" should be band Col. 2, line 55, "560" should be 650 Col. 6, line 11, insert eccentric after "rotatable" Signed and sealed this 11 th day of April 1972.

(SEAL) Attest:

EDWAHD M.FLETCHHI, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents IORM po'wso USCOMM-DC scan-Pea Q U.S. GOVERNMENT PRINTING OFFICE I I0. O3I6!!l 

1. In a portable spray gun having a handle, a self-contained motor, a motor housing, a liquid supply container secured thereto, rotary means for discharging liquid from the spray gun peripherally of the rotary means and a movable gating mechanism for adjusting the width of the spray pattern discharged from the rotary means, a movable trigger means, means operatively connected to said trigger means upon movement thereof for actuating said motor and means operatively connected to said trigger for moving said gating mechanism after said motor has been actuated between a closed position and a preselectable range of open positions to preselect the width of the spray pattern discharged from said spray gun.
 2. In the spray gun of claim 1 wherein said gating mechanism comprises a pair of gate members having peripheral shielding flanges in the path of liquid discharged from said rotary means when the gating mechanism is in a closed position.
 3. In the spray gun of claim 2 in which each of said gate members defines a slot eccentric to a central axis of said gate members, and said gate moving means includes a pin member in said slots.
 4. In the spray gun of claim 3 in which said said pin member is secured to a reciprocable gate link operatively connected to said trigger means, said gate link being reciprocably movable with said trigger means.
 5. In the spray gun of claim 1 further including externally adjustable means for limiting the range of movement of said trigger means thereby to preselect the width of the spray pattern discharged by said rotary means through said gating mechanism.
 6. In a manual spray gun having a handle, a motor housing connected to the handle, a motor in the housing, rotor means for discharging liquid peripherally therefrom, means for supplying said rotor means with liquid to be sprayed, and a gating mechanism through which liquid discharged by said rotor means is adapted to pass, a trigger, said gating mechanism comprising a pair of oscillatable gates oscillatable between a closed position to intercept all of the liquid discharged by said rotor means and a range of preselectable open positions to allow discharge of liquid from said spray gun, and means for oscillating said gates connected to said trigger and to said gates.
 7. In the spray gun of claim 6 wherein said oscillating means comprises a gate link and channels in said gates, said channels being eccentric to the axis about which said gates oscillate.
 8. In the spray gun of claim 7 wherein said gate link is reciprocably movable with said trigger and mounts a gate pin positioned in said channels.
 9. In the spray gun of claim 6 further including means for energizing said motor prior to oscillation of said gates connected to said trigger.
 10. In the spray gun of claim 6 wherein said spray gun mounts a rotatable cam, said cam being positioned to contact said trigger and to limit the movement of said trigger to any one of said range of preselectable open positions thereby to preselect the width of the spray pattern discharged through said gating mechanism. 